Auto add a user after the registr. to a group accordingly to custom field value

[zavag]

I am running SMF2 RC1-1

The forum I am designing is for a school. I have created some special membergroups named "Teachers of School", "Other Teachers", "Students of school", "Other students" and "Others". So I want every person who make registration to have some extra fields (required) to fill in order to describe its identity (student/teacher etc) to help me to categorize the members who subscribe in the forum. I didn't notice that I could add some fields at the registration procedure.
So I add a radio-button (name:MemberIdentity) with 4 possible answers and i make it as required (not optional)

Something else about this:
Is it possible to add automatically the user after the registration to a membergroup accordingly to the value of "MemberIdentity" ... I didn't find any option (even on members search) with these fields...

I am trying to combine the fields with SQL from database tables ... but ... i couldn't manage with it ... and of course this query must include to some (or one) of PHP programs ...
Also i didn't find any MOD for this ...

[Liam.]

So have you actually gotten this to work, because it sounds like you have from your post. If not, I'll PM you the answers in a few minutes...

One issue with this however, is someone can sign up from halfway across the world and put themselves in the "Teachers" group and boss others around. Or students can do that. I see that as a large issue with what you are attempting to do.

[zavag]

I know that anyone can sign-up to "teachers" group without any other confirmation... Is it possible to check the new user with, for example, password (I mean that these groups must have a password) ?
Is there another technique to achieve my target?